Updating a palette results in deleting undo/redo history

In MS 3, if I reordered items in a palette or do other customization, then I can use it in all scores. MS 4 opens a separate instance of app for each score, so to update palette and use it everywhere I need to
1) close all other windows (which forces me to save and I loose all undo/redo history)
2) close the window with updated palette so it saves settings
3) reopen all scores.

Imagine if there are ten or more of them...
It's even worse if I accidentally customize a palette in two windows because then I inevitably loose the changes.

I intentionally don't say anything about UX problem because it seems to be by design (???), but this is a serious functional issue (data loss)

Related to https://musescore.org/en/node/338910

Greetings and thanks for a huge update!